java - 在 primefaces 数据表中选择行

Question

我有这张表:

<h:form>
    <p:dataTable id="books" value="#{ordersBean.userOrders}" var="book" selection="#{ordersBean.selectedBook}">
        <p:column>
            <f:facet name="header">Order ID</f:facet>
            <h:outputText value="#{book[0]}"/>
        </p:column>
        <p:column>
            <f:facet name="header">Title</f:facet>
            <h:outputText value="#{book[1]}"/>
        </p:column>
        <p:column>
            <f:facet name="header"></f:facet>
            <p:commandButton id="selectRowBtn" value="select" action="#{ordersBean.showSelectedBook}"/>
        </p:column>
    </p:dataTable>
</h:form>

我希望当我点击每个 select 按钮时，它是分配给 selectedBook 属性的行信息，并在 showSelectedBook() 方法中显示它:

这是ordersBean:

private Book selectedBook = new Book();

public Book getSelectedBook() {
    return selectedBook;
}

public void setSelectedBook(Book selectedBook) {
    this.selectedBook = selectedBook;
}

public void showSelectedBook() {
    System.out.println("In selected Book(), book: " + getSelectedBook());
}

但结果是这样的:

在选定的 Book() 中，book: null

Answer 1

应该是这样的:

XML代码:

<p:commandButton id="selectRowBtn" value="select" 
    action="#{ordersBean.showSelectedBook}">
    <f:param name="bookId" value="#{book[0]}" />
</p:commandButton>

Java bean 方法:

public void showSelectedBook() {

    Map<String,String> params = 
        FacesContext.getExternalContext().getRequestParameterMap();

    int bookId = Integer.valueOf(params.get("bookId"));

    for(Book book : bookList){
        if(book.bookId == bookId){
            selectedBook = book;
            break;
        }
    }

    System.out.println("In selected Book(), book: " + getSelectedBook());
}

此外，您必须了解将参数发送到操作的模式，请参阅下面的链接。 http://www.mkyong.com/jsf2/4-ways-to-pass-parameter-from-jsf-page-to-backing-bean/